Thin film magnetic head, method of manufacturing the same, and magnetic disk drive

ABSTRACT

Provided are a thin film magnetic head capable of inhibiting an excessive temperature rise while reducing its size in accordance with a higher recording density, and obtaining a higher read output, a method of manufacturing the same, and a magnetic disk drive using the thin film magnetic head. A heat dissipation layer for transferring heat generated in a magnetic transducer film to outside is disposed adjacent to the magnetic transducer film on a side, the side being opposite to a side facing a recording medium. In a gap layer for electrically insulating between the magnetic transducer film and a pair of shield layers, a portion of the gap layer in contact with an end surface of the magnetic transducer film on a side, the side being opposite to a side facing the recording medium is formed so as to have a thin thickness ranging from 2 nm to 30 nm inclusive. Thereby, the heat generated in the magnetic transducer film can be more effectively dissipated than previously possible, and a temperature rise can be inhibited. Therefore, an increase in electrical resistance can be inhibited, and a higher read output can be obtained.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a thin film magnetic head havinga function of dissipating heat generated in a magnetoresistive effectfilm to outside, a method of manufacturing the same, and a magnetic diskdrive comprising the thin film magnetic head.

[0003] 2. Description of the Related Art

[0004] In recent years, an improvement in performance of thin filmmagnetic heads has been sought in accordance with an improvement inareal density of hard disk drives. As the thin film magnetic heads,composite thin film magnetic heads (hereinafter simply referred to as“thin film magnetic heads”) are widely used. The composite thin filmmagnetic head comprises a laminate including a reproducing head portionhaving a magnetoresistive device (hereinafter referred to “MR device”),which is a kind of magnetic transducer, and a recording head portionhaving an inductive magnetic transducer.

[0005] As a typical MR device, a GMR device using a magnetic film (GMRfilm) exhibiting a giant magnetoresistive effect (hereinafter referredto as “GMR effect”) is cited. In particular, a GMR device using aspin-valve type GMR film has been in the mainstream. The spin-valve typeGMR film has a relatively simple structure, thereby is suitable for massproduction, and exhibits a large change in magnetoresistance in spite ofan extremely weak magnetic field. Such a GMR device has the followingstructure.

[0006]FIG. 18 shows a schematic sectional view of a structure of aconventional reproducing head portion including the GMR film. Areproducing head portion 110A has the following structure. On a basesubstrate (not shown) made of, for example, AlTiC (Al₂O₃—TiC) or thelike, a bottom shield layer 101 made of a magnetic material is laminatedwith an insulating layer (not shown) made of, for example, aluminumoxide (Al₂O₃) or the like in between. On the bottom shield layer 101, abottom gap layer 102 made of, for example, an insulating material suchas aluminum oxide or the like is formed, and on the bottom gap layer102, a GMR film 120 and an insulating layer 103 are formed so as to beadjacent to each other. On the GMR film 120 and the insulating layer103, a top gap layer 105 is laminated. A bottom surface and a topsurface of the GMR film 120 are in contact with the bottom gap layer 102and the top gap layer 105, respectively. On one side end surface of theGMR film 120, a recording-medium-facing surface 119 facing a magneticrecording medium 11 is formed, and an end surface of the GMR film 120 ona side opposite to the recording-medium-facing surface 119 is in contactwith the insulating layer 103. As in the case of the GMR film 120, abottom surface and a top surface of the insulating layer 103 are incontact with the bottom gap layer 102 and the top gap layer 105,respectively. Further, on the top gap layer 105, a top shield layer 106made of a magnetic material is laminated.

[0007] On the reproducing head portion 110A, a recording head portion(not shown) is laminated, and the combination of the reproducing headportion 110A and the recording head portion constitutes a thin filmmagnetic head 110.

[0008] In general, a length from the recording-medium-facing surface 119to an end surface on a side opposite to the recording-medium-facingsurface 119 in the MR device is called an MR height (or an MR deviceheight). On the other hand, a length of the MR device in a directionperpendicular to a paper surface of FIG. 18 is a portion correspondingto a track width of a recording medium (hereinafter referred to as “MRdevice width”). Recently, in order to cope with a remarkable increase inrecording density, the MR device width is becoming increasingly smaller.Accordingly, the MR height is also becoming increasingly smaller.

[0009] A problem resulting from heat generated in the MR device occursdue to a downsizing of the MR device. The problem is that due to theheat generated in the MR device, electromigration (a phenomenon in whicha void is locally formed when metal atoms move in a conductor) orinterlayer diffusion is induced, and as a result, it is difficult tosufficiently extend the lifetime of the MR device. The heat generated inthe GMR device 120 is transferred to the top shield layer 106 and thebottom shield layer 101 through the top gap layer 105 and the bottom gaplayer 102 to be dissipated. However, when the MR height and the MRdevice width become smaller, a heat dissipation area, that is, the wholesurface area of the GMR film 120 is greatly reduced as a inevitableconsequence, so sufficient heat dissipation can not be achieved. It canbe considered that when the MR device becomes still thinner (smaller) infuture, the temperature of the MR device will excessively rise to, forexample, higher than 50° C., and as a result, electrical resistance ofthe thin film magnetic head will increase. In extreme cases, elementdiffusion may occur in the MR device, thereby characteristics of thinfilm magnetic head may be pronouncedly degraded. Further, it can beconsidered that even if the temperature of the MR film does not rise toas high as internal element diffusion occurs, a degradation in thecharacteristics resulting from the heat generated in the GMR film 120such as a reduction in output during reproducing magnetically recordedinformation resulting from increased electrical resistance may occur.

[0010] As an MR device with improved heat dissipation, for example, athin film magnetic head disclosed in Japanese Unexamined PatentApplication Publication No. Hei 6-223331 is cited. In the thin filmmagnetic head disclosed in the publication, as an insulating layer of anMR device, a material with good insulation and good thermal conductivitysuch as a silicon film, a diamond-like carbon or the like is used so asto carry out heat dissipation of the MR device. Moreover, in a thin filmmagnetic head and a magnetic disk drive disclosed in Japanese UnexaminedPatent Application Publication No. 10-222816, as not only an insulatinglayer of an MR device, but also a protective film of a magnetic headslider or a disk surface, a non-magnetic insulating film with a highheat dissipation ratio such as a hydrogen-containing amorphous carbonfilm, silicon-containing amorphous carbon, amorphous aluminum nitride orthe like is used. Thereby, the occurrence of a phenomenon called thermalasperity (TA) resulting from heat caused by friction between themagnetic head slider and the magnetic disk, electromigration or the likecan be prevented, so the characteristics of read output can be improved.However, even if the thermal conductivity of a component material aroundthe MR device is higher, the heat dissipation area of the componentaround the MR device is relatively reduced resulting from a downsizingof the MR device, so heat dissipation capacity is limited.

[0011] The applicant of the present invention has been proposed a thinfilm magnetic head disclosed in Japanese Unexamined Patent ApplicationPublication No. 2000-353308, which can overcome the above-describedproblem. An enlarged sectional view of a specific example of the thinfilm magnetic head disclosed in the publication is shown in FIG. 19. Inthe thin film magnetic head, a reproducing head portion 210A comprises aheat dissipation layer 104 in contact with a laminated surface of theGMR film 120, and heat generated in the GMR film 120 is dissipated tooutside through the heat dissipation layer 104.

[0012] However, even in the case of the thin film magnetic headdisclosed in the above publication, when a demand for a thinner MRdevice (a downsizing of the MR film in a thickness direction) grows inaccordance with an even higher recording density in future, the heatdissipation layer 104 cannot have a sufficient thickness, and as aresult, it can be expected that it will be more difficult to securesufficient heat dissipation.

SUMMARY OF THE INVENTION

[0013] In view of the foregoing, it is an object of the invention toprovide a thin film magnetic head capable of inhibiting an excessiverise in temperature while reducing its size in accordance with a higherrecording density, and obtaining a higher read output, a method ofmanufacturing the same, and a magnetic disk drive using the thin filmmagnetic head.

[0014] A thin film magnetic head according to a first aspect of theinvention comprises: a magnetic transducer film being disposed so thatan end surface thereof faces a recording medium, and detecting a signalmagnetic field from the recording medium; and a heat dissipation layerbeing disposed adjacent to the magnetic transducer film on a side, theside being opposite to a side facing the recording medium, andtransferring heat generated in the magnetic transducer film to outside.

[0015] In the thin film magnetic head according to the first aspect ofthe invention, a magnetic transducer film being disposed so that an endsurface thereof faces a recording medium, and detecting a signalmagnetic field from the recording medium, and a heat dissipation layerbeing disposed adjacent to the magnetic transducer film on a side, theside being opposite to a side facing the recording medium, andtransferring heat generated in the magnetic transducer film to outsideare comprised, so the heat generated in the magnetic transducer film canbe effectively dissipated, and a temperature rise can be inhibited.

[0016] A thin film magnetic head according to a second aspect of theinvention comprises: a magnetic transducer film being disposed so thatan end surface thereof faces a recording medium, and detecting a signalmagnetic field from the recording medium; a pair of shield layers beingdisposed so as to surround an end surface of the magnetic transducerfilm on a side opposite to the end surface thereof, and film surfaces ofthe magnetic transducer film facing each other, and magneticallyshielding the magnetic transducer film; and a gap layer being disposedbetween the magnetic transducer film and the pair of shield layers, andelectrically insulating therebetween, wherein a portion of the gap layerin contact with the end surface of the magnetic transducer film on aside, the side being opposite to a side facing the recording medium hasa thickness ranging from 2 nm to 30 nm inclusive.

[0017] In the thin film magnetic head according to the second aspect ofthe invention, a magnetic transducer film being disposed so that an endsurface thereof faces a recording medium, and detecting a signalmagnetic field from the recording medium, a pair of shield layers beingdisposed so as to surround an end surface of the magnetic transducerfilm on a side opposite to the end surface thereof, and film surfaces ofthe magnetic transducer film facing each other, and magneticallyshielding the magnetic transducer film, and a gap layer being disposedbetween the magnetic transducer film and the pair of shield layers, andelectrically insulating therebetween are comprised, and a portion of thegap layer in contact with the end surface of the magnetic transducerfilm on a side, the side being opposite to a side facing the recordingmedium has a thickness ranging from 2 nm to 30 nm inclusive, so heatgenerated in the magnetic transducer film can be effectively dissipated,and a temperature rise can be inhibited.

[0018] In a method of manufacturing a thin film magnetic head accordingto a first aspect of the invention, the thin film magnetic headcomprises a magnetic transducer film being disposed so that an endsurface thereof faces a recording medium, and detecting a signalmagnetic field from the recording medium, and the method comprises thesteps of: forming the magnetic transducer film; and forming a heatdissipation layer for transferring heat generated in the magnetictransducer film to outside so as to be disposed adjacent to the magnetictransducer film on a side, the side being opposite to a side facing therecording medium.

[0019] The method of manufacturing a thin film magnetic head accordingto the first aspect of the invention comprises the steps of forming amagnetic transducer film, and forming a heat dissipation layer fortransferring heat generated in the magnetic transducer film to outsideso as to be disposed adjacent to the magnetic transducer film on a side,the side being opposite to a side facing the recording medium, so theheat generated in the magnetic transducer film can be effectivelydissipated, and a temperature rise can be inhibited.

[0020] In a method of manufacturing a thin film magnetic head accordingto a second aspect of the invention, the thin film magnetic headcomprises a magnetic transducer film being disposed so that an endsurface thereof faces a recording medium, and detecting a signalmagnetic field from the recording medium, a pair of shield layersmagnetically shielding the magnetic transducer film, and a gap layerelectrically insulating between the magnetic transducer film and thepair of shield layers, and the method comprises the steps of forming themagnetic transducer film; forming the pair of shield layers so as tosurround an end surface of the magnetic transducer film on a sideopposite to the end surface, and film surfaces of the magnetictransducer film facing each other; and forming the gap layer between themagnetic transducer film and the pair of shield layers so that a portionof the gap layer in contact with the end surface of the magnetictransducer film on a side, the side being opposite to a side facing therecording medium has a thickness ranging from 2 nm to 30 nm inclusive.

[0021] The method of manufacturing a thin film magnetic head accordingto the second aspect of the invention comprises the steps of forming amagnetic transducer film, forming a pair of shield layers so as tosurround the magnetic transducer film except for an end surface of themagnetic transducer film, and forming a gap layer between the magnetictransducer film and the pair of shield layers so that a portion of thegap layer in contact with the end surface of the magnetic transducerfilm on a side, the side being opposite to a side facing the recordingmedium has a thickness ranging from 2 nm to 30 nm inclusive, so heatgenerated in the magnetic transducer film can be effectively dissipated,and a temperature rise can be inhibited.

[0022] A magnetic disk drive according to a first aspect of theinvention comprises: a recording medium; and a thin film magnetic head,wherein the film magnetic head comprises a magnetic transducer filmbeing disposed so that an end surface thereof faces the recordingmedium, and detecting a signal magnetic field from the recording medium,and a heat dissipation layer being disposed adjacent to the magnetictransducer film on a side, the side being opposite to a side facing therecording medium, and transferring heat generated in the magnetictransducer film to outside.

[0023] In the magnetic disk drive according to the first aspect of theinvention, the thin film magnetic head comprises a magnetic transducerfilm being disposed so that an end surface thereof faces the recordingmedium, and detecting a signal magnetic field from the recording medium,and a heat dissipation layer being disposed adjacent to the magnetictransducer film on a side, the side being opposite to a side facing therecording medium, and transferring heat generated in the magnetictransducer film to outside, so the heat generated in the magnetictransducer film can be effectively dissipated, and a temperature risecan be inhibited.

[0024] A magnetic disk drive according to a second aspect of theinvention comprises: a recording medium; and a thin film magnetic head,wherein the thin film magnetic head comprises a magnetic transducer filmbeing disposed so that an end surface thereof faces the recordingmedium, and detecting a signal magnetic field from the recording medium,a pair of shield layers being disposed so as to surround an end surfaceof the magnetic transducer film on a side opposite to the end surfacethereof, and film surfaces of the magnetic transducer film facing eachother, and magnetically shielding the magnetic transducer film, a gaplayer being disposed between the magnetic transducer film and the pairof shield layers, and electrically insulating therebetween, wherein aportion of the gap layer in contact with the end surface of the magnetictransducer film on a side, the side being opposite to a side facing therecording medium has a thickness ranging from 2 nm to 30 nm inclusive.

[0025] In the magnetic disk drive according to the second aspect of theinvention, the thin film magnetic head comprises a magnetic transducerfilm being disposed so that an end surface thereof faces the recordingmedium, and detecting a signal magnetic field from the recording medium,a pair of shield layers being disposed so as to surround an end surfaceof the magnetic transducer film on a side opposite to the end surfacethereof, and film surfaces of the magnetic transducer facing each other,and magnetically shielding the magnetic transducer film, and a gap layerbeing disposed between the magnetic transducer film and the pair ofshield layers, and electrically insulating therebetween, wherein aportion of the gap layer in contact with the end surface of the magnetictransducer film on a side, the side being opposite to a side facing therecording medium has a thickness ranging from 2 nm to 30 nm inclusive,so heat generated in the magnetic transducer film can be effectivelydissipated, and a temperature rise can be inhibited.

[0026] In the thin film magnetic head or the method of manufacturing athin film magnetic head according to the first aspect of the invention,an insulating layer may be comprised between the magnetic transducerfilm and the heat dissipation layer. In this case, a portion of theinsulating layer in contact with an end surface of the magnetictransducer film on a side, the side being opposite to a side facing therecording medium preferably has a thickness ranging from 2 nm to 30 nminclusive.

[0027] In the thin film magnetic head or the method of manufacturing athin film magnetic head according to the first aspect of the invention,the heat dissipation layer is preferably made of a material with ahigher thermal conductivity than that of the insulating layer, morepreferably a non-magnetic metallic material. More specifically, the heatdissipation layer preferably includes at least one selected from thegroup consisting of silver (Ag), aluminum (Al), gold (Au), beryllium(Be), bismuth (Bi), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe),indium (In), iridium (Ir), magnesium (Mg), manganese (Mn), molybdenum(Mo), niobium (Nb), nickel (Ni), palladium (Pd), platinum (Pt), rhenium(Re), antimony (Sb), selenium (Se), tantalum (Ta), tellurium (Te),thorium (Th), titanium (Ti), thallium (Tl), vanadium (V), tungsten (W),yttrium (Y) and zirconium (Zr).

[0028] In the thin film magnetic head or the method of manufacturing athin film magnetic head according to the first aspect of the invention,the heat dissipation layer is preferably formed so as to have athickness corresponding to at least half of the thickness of themagnetic transducer film.

[0029] In the thin film magnetic head or the method of manufacturing athin film magnetic head according to the first aspect of the invention,a pair of shield layers being disposed so as to face each other with themagnetic transducer film in between in a laminated direction, andmagnetically shielding the magnetic transducer film may be furthercomprised. In this case, a distance between the heat dissipation layerand each of the pair of shield layers is preferably 2 nm or over.

[0030] In the thin film magnetic head or the method of manufacturing athin film magnetic head according to the first aspect of the invention,a pair of gap layers being disposed between the magnetic transducer filmand the pair of shield layers, and electrically insulating between themagnetic transducer film and the pair of shield layers may be furthercomprised. In this case, the insulating layer is preferably made of thesame material as that of the pair of gap layers.

[0031] In the thin film magnetic head or the method of manufacturing athin film magnetic head according to the second aspect of the invention,it is preferable that the pair of shield layers occupy a spacecorresponding to at least half of the thickness of the magnetictransducer film, and have a distance of at least 2 nm therebetween.

[0032] Other and further objects, features and advantages of theinvention will appear more fully from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 is a schematic view of a magnetic disk drive according to afirst embodiment of the invention;

[0034]FIG. 2 is a perspective view of a magnetic head slider comprisinga thin film magnetic head according to the first embodiment of theinvention;

[0035]FIG. 3 is a plan view of the thin film magnetic head according tothe first embodiment of the invention;

[0036]FIG. 4 is a sectional view of the thin film magnetic head takenalong a line IV-IV of FIG. 3;

[0037]FIG. 5 is a sectional view of the thin film magnetic head takenalong a line V-V of FIGS. 3 and 4;

[0038]FIG. 6 is an enlarged sectional view of the thin film magnetichead according to the first embodiment of the invention in a directionperpendicular to a recording-medium-facing surface;

[0039]FIG. 7 is a plot showing a correlation between a thickness A of aninsulating layer 3 and an MR height in the thin film magnetic head shownin FIG. 6;

[0040]FIG. 8 is a plot showing a correlation between a thickness C of aheat dissipation layer 4 and the MR height in the thin film magnetichead shown in FIG. 6;

[0041]FIG. 9 is a plot showing a correlation between the MR height and araised temperature in the thin film magnetic head shown in FIG. 6;

[0042]FIG. 10 is a plot showing a correlation between the MR height andan output voltage in the thin film magnetic head shown in FIG. 6;

[0043]FIG. 11 is a flowchart showing a method of manufacturing the thinfilm magnetic head according to the first embodiment of the invention;

[0044]FIG. 12 is a sectional view showing one step in the method ofmanufacturing the thin film magnetic head according to the firstembodiment of the invention;

[0045]FIG. 13 is a sectional view showing a step following the stepshown in FIG. 12;

[0046]FIG. 14 is a sectional view showing a step following the stepshown in FIG. 13;

[0047]FIG. 15 is a sectional view showing a step following the stepshown in FIG. 14;

[0048]FIG. 16 is a sectional view showing a step following the stepshown in FIG. 15;

[0049]FIG. 17 is an enlarged sectional view of a thin film magnetic headaccording to a second embodiment of the invention in a directionperpendicular to a recording-medium-facing surface;

[0050]FIG. 18 is an enlarged sectional view of a conventional thin filmmagnetic head in a direction perpendicular to a recording-medium-facingsurface; and

[0051]FIG. 19 is an enlarged sectional view of a thin film magnetic headas a comparative example in a direction perpendicular to arecording-medium-facing surface.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] Preferred embodiments of the present invention will be describedin more detail below referring the accompanying drawings.

[0053] [First Embodiment]

[0054] Referring to FIGS. 1 and 2, a magnetic disk drive using a thinfilm magnetic head according to a first embodiment of the invention willbe described below. FIG. 1 shows a structure of a magnetic disk driveaccording to the first embodiment. In the embodiment, a magnetic diskdrive using an operation mode called a CSS (contact-start-stop)operation mode is described as an example. The magnetic disk drivecomprises a plurality of magnetic recording media 11 and a plurality ofmagnetic head apparatuses 12 each being disposed corresponding to asurface of each of the plurality of magnetic recording media 11. Herein,each of the magnetic recording media 11 corresponds to a specificexample of “a recording medium” in the invention. The magnetic recordingmedia 11 rotate by use of a spindle motor 14 fixed on a case 13. Themagnetic head apparatuses 12 are mounted on a fixed shaft 15 fixed onthe case 13 so as to be able to rotate with a bearing 16. Herein, theplurality of magnetic head apparatuses 12 are mounted on the fixed shaft15 through the common bearing 16, so the plurality of magnetic headapparatuses 12 rotate as a unit. A magnetic head slider 17 (hereinaftersimply referred to as slider 17) is mounted on a front end side of eachof the magnetic head apparatuses 12. The magnetic disk drive furthercomprises a driving portion 18 on a rear end side of the magnetic headapparatuses 12, the driving portion 18 being for positioning the slider17 on a track of each of the magnetic recording media 11. The drivingportion 18 makes the magnetic head apparatuses 12 rotate around thefixed shaft 15 as a center, and the slider 17 can be moved in a radialdirection of the magnetic recording medium 11 by the driving portion 18.

[0055]FIG. 2 shows an enlarged perspective view of the slider 17 shownin FIG. 1. The slider 17 has a base substrate 100 formed of, forexample, AlTiC (Al₂O₃—TiC) in a substantially hexahedron shape. Asurface of the slider 17 facing the magnetic recording medium 11 is arecording-medium-facing surface or an air bearing surface (ABS) 19. Asshown in FIG. 2, a thin film magnetic head 10 is disposed on one sidesurface of the slider 17 orthogonal to the ABS 19.

[0056] Next, recording and reproducing by the magnetic disk drive withsuch a structure will be described below referring to FIG. 1. In the CSSoperation mode, when the magnetic disk drive is not in operation, thatis, in a state that the spindle motor 14 stops, so the magneticrecording medium 11 does not rotate, the ABS 19 of the slider 17 comesinto contact with the magnetic recording medium 11. When recording andreproducing are performed, the magnetic recording medium 11 is rotatedat high speed by the spindle motor 14. When the magnetic recordingmedium 11 rotates at high speed, an airflow occurs, thereby liftingpower is generated. While the slider 17 is floated from the surface ofthe magnetic recording medium 11 by the lifting power, the slider 17 isrelatively moved in a direction horizontal to the surface of themagnetic recording medium 11 by the driving portion 18. At this time,recording and reproducing are performed by the thin film magnetic head10 formed on one side surface of the slider 17.

[0057] Next, referring to FIGS. 3 through 5, the thin film magnetic head10 according to the embodiment will be described in more detail below.

[0058]FIG. 3 shows an enlarged plan view of the thin film magnetic head10 formed on one side surface of the slider 17 (refer to FIG. 2). FIG. 4is a sectional view taken along a line IV-IV shown in FIG. 3. FIG. 5 isa sectional view taken along a line V-V shown in FIGS. 3 and 4. As shownin FIG. 4, the thin film magnetic head 10 comprises a laminate includinga reproducing head portion 10A and a recording head portion 10B in orderfrom the base substrate 100. The reproducing head portion 10A reproducesmagnetic information recorded on the magnetic recording medium 11, onthe other hand, the recording head portion 10B records magneticinformation on a track of the magnetic recording medium 11.

[0059] At first, the structure of the reproducing head portion 10A willbe described below referring to FIGS. 4 and 5. As shown in FIG. 4, thereproducing head portion 10A comprises, for example, a laminateincluding a bottom shield layer 1, a bottom gap layer 2, a GMR film 20,a top gap layer 5 and a top shield layer 6 in order on the basesubstrate 100 on a side exposed to the ABS 19.

[0060] The bottom shield layer 1 is made of, for example, a magneticmaterial such as a nickel iron alloy (NiFe) or the like, and has afunction of preventing an influence of an unnecessary magnetic field onthe GMR film 20 to be described later. The bottom gap layer 2 is made ofan insulating material such as aluminum oxide (A1 ₂O₃), aluminum nitride(AlN) or the like to insulate between the bottom shield layer 1 and theGMR film 20. The GMR film 20 according to the embodiment corresponds toa specific example of “a magnetic transducer film” in the invention,which will be described later. As in the case of the bottom gap layer 2,the top gap layer 5 is made of an insulating material to insulatebetween the top shield layer 6 and the GMR film 20. As in the case ofthe bottom shield layer 1, the top shield layer 6 is made of a magneticmaterial such as a nickel iron alloy (NiFe) or the like, and has afunction of preventing the influence of an unnecessary magnetic field onthe GMR film 20. The top shield layer 6 also has a function as a bottompole in the recording head portion 10B.

[0061] The GMR film 20 is a spin-valve type GMR film with a multilayerstructure including a magnetic material, and has a function of readinginformation recorded on the magnetic recording medium 11. A bottomsurface and a top surface of the GMR film 20 are in contact with thebottom gap layer 2 and the top gap layer 5, respectively. In thereproducing head portion 10A, the information recorded on the magneticrecording medium 11 is reproduced by use of a change in electricalresistance of the GMR film 20 in accordance with a signal magnetic fieldfrom the magnetic recording medium 11.

[0062] As shown in FIG. 5, a pair of magnetic domain control layers 31Aand 31B (hereinafter collectively referred to as “magnetic domaincontrol layers 31”) extend on both sides of the GMR film 20 on thebottom gap layer 2. On the magnetic domain control layers 31, a pair offirst lead layers 32A and 32B (hereinafter collectively referred to as“first lead layers 32”) are formed, and on the first lead layers 32, apair of second lead layers (not shown) are selectively formed so as toform a GMR device 10C. The magnetic domain control layers 31 are made ofa hard magnetic material including a cobalt platinum alloy (CoPt) or thelike, and extends on both sides of the GMR film 20 in a directioncorresponding to a recording track width direction. The magnetic domaincontrol layers 31 have a function of preventing the occurrence ofBarkhausen noise through aligning directions of magnetic domains of amagnetic sensing layer 25 so as to form a single magnetic domain. Thefirst lead layers 32 function as current paths for flowing a sensecurrent into the GMR film 20 through the magnetic domain control layers31, and are connected to electrodes EA and EB (refer to FIG. 3) throughthe second lead layers (not shown), respectively.

[0063] As shown in FIG. 5, the GMR film 20 comprises, for example, alaminate including a base layer 21, a pinning layer 22, a pinned layer23, a non-magnetic layer 24, the magnetic sensing layer 25 called a freelayer and a cap layer 26 in order on the bottom gap layer 2.

[0064] The base layer 21 is made of, for example, tantalum (Ta) or thelike with a thickness of 5 nm. The pinning layer 22 is made of anantiferromagnetic material such as a platinum manganese alloy (PtMn) orthe like, and has a function of pinning the direction of magnetizationof the pinned layer 23. The pinned layer 23 made of a cobalt iron alloy(CoFe) is a magnetic layer of which the direction of magnetization ispinned by exchange coupling in an interface with the pinning layer 22.The non-magnetic layer 24 is made of, for example, a non-magneticmetallic material such as copper (Cu), gold (Au) or the like with athickness of 3 nm. The magnetic sensing layer 25 is made of, forexample, a cobalt iron alloy (CoFe) or the like with a thickness of 2nm, and the direction of magnetization of the magnetic sensing layer 25changes in accordance with a signal magnetic field from the magneticrecording medium 11. The cap layer 26 is made of, for example, tantalumor the like with a thickness of 1 nm.

[0065] In the reproducing head portion 10A with such a structure, thedirection of magnetization of the magnetic sensing layer 25 changes inaccordance with the signal magnetic field from the magnetic recordingmedium 11, so a relative change in connection with the direction ofmagnetization of the pinned layer 23 fixed in one direction by thepinning layer 22 occurs. At this time, when a sense current flowsthrough the GMR film 20, a change in the direction of magnetizationshows up as a change in electrical resistance. The signal magnetic fieldis detected by using the change so as to reproduce magnetic information.

[0066] Next, the structure of the recording head portion 10B will bedescribed below. As shown in FIG. 4, the recording head portion 10Bcomprises the top shield layer 6 functioning as a bottom pole, a writegap layer 41, coils 43 and 45, photoresist layers 42, 44 and 46, and atop pole 47.

[0067] The write gap layer 41 is made of an insulating layer such asaluminum oxide or the like, and is formed on the top shield layer 6. Thewrite gap layer 41 has an opening 41A (refer to FIGS. 3 and 4) forforming a magnetic path in a position corresponding to central portionsof the coils 43 and 45. The coil 43 is formed around the opening 41A asa center on the write gap layer 41 with the photoresist layer 42 inbetween. Moreover, the photoresist layer 44 is formed in a predeterminedpattern so the coil 43 is covered with the photoresist layer 44. On thephotoresist layer 44, the coil 45 and the photoresist layer 46 withwhich the coil 45 is covered are formed. Herein, an end of the coil 43and an end of the coil 45 are electrically connected to each other in aconnecting portion (not shown) to function as a series of coils.Further, the other ends of the coils 43 and 45 are connected toelectrodes 43E and 45E, respectively (refer to FIG. 3).

[0068] On the write gap layer 41, the opening 41A and the photoresistlayers 42, 44 and 46, the top pole 47 made of, for example, a magneticmaterial with a high saturation magnetic flux density such as a NiFealloy, iron nitride (FeN) or the like is formed. The top pole 47 is incontact with and is magnetically coupled to the top shield layer 6through the opening 41A. Further, an overcoat layer (not shown) made ofaluminum oxide or the like is formed so that the whole top surface ofthe recording head portion 10B is covered with the overcoat layer.

[0069] The recording head portion 10B with such a structure generatesmagnetic flux in a magnetic path including the top shield layer 6 andthe top pole 47 by a current flowing through the coils 43 and 45, andmagnetizes the magnetic recording medium 11 by a signal magnetic fieldgenerated in the vicinity of the write gap layer 41 by the magnetic fluxso as to record information.

[0070] Next, referring to FIG. 6, the structure of a region in thevicinity of the GMR film 20 which is an important characteristic part ofthe invention will be described in detail below. FIG. 6 shows anenlarged sectional view of the GMR film 20 and its surroundings in thethin film magnetic head 10 shown in FIG. 4.

[0071] As shown in FIG. 6, the heat dissipation layer 4 having afunction of dissipating the heat generated in the GMR film 20 is formedbetween the bottom gap layer 2 and the top gap layer 5 on a sideadjacent to the GMR film 20 opposite to the ABS 19. Further, theinsulating layer 3 is disposed between the GMR film 20 and the heatdissipation layer 4. The heat dissipation layer 4 is made of a materialwith a higher thermal conductivity than the insulating layer 3, morepreferably a non-magnetic metallic material. More specifically, the heatdissipation layer 4 is preferably made of a material including at leastone selected from the group consisting of elements shown in Table 1 suchas, for example, bismuth (Bi), tantalum (Ta), platinum (Pt), palladium(Pd) or the like. Moreover, the heat dissipation layer 4 preferably hasa thickness C which is at least half of the thickness of the GMR film20, and a distance B between the heat dissipation layer 4 and the bottomshield layer 1 is preferably 2 nm or over. The distance between the heatdissipation layer 4 and the top shield layer 6, that is, a thickness ofthe top gap layer 5 is also preferably 2 nm or over. It is a minimumdistance required to secure insulation between the heat dissipationlayer 4 and the bottom shield layer 1, or between the heat dissipationlayer 4 and the top shield layer 6. The amounts of the distance B andthe thickness C will be described in detail later. TABLE 1 Material usedfor Thermal conductivity heat dissipation layer [J/mKs] Silver (Ag)420.0 Aluminum (Al) 223.0 Gold (Au) 298.0 Beryllium (Be) 18.9 Bismuth(Bi) 8.4 Cobalt (Co) 69.3 Chromium (Cr) 67.2 Copper (Cu) 395.0 Iron (Fe)75.6 Indium (In) 23.9 Iridium (Ir) 58.8 Magnesium (Mg) 160.0 Manganese(Mn) 7.2 Molybdenum (Mo) 147.0 Niobium (Nb) 52.5 Nickel (Ni) 92.4Palladium (Pd) 71.4 Platinum (Pt) 71.4 Rhenium (Re) 71.4 Antimony (Sb)18.9 Selenium (Se) 2.9 Tantalum (Ta) 54.6 Tellurium (Te) 5.9 Thorium(Th) 37.8 Titanium (Ti) 17.1 Thallium (Tl) 39.1 Vanadium (V) 31.1Tungsten (W) 167.0 Yttrium (Y) 10.1 Zirconium (Zr) 4.2

[0072] The insulating layer 3 is made of, for example, an insulatingmaterial such as aluminum oxide (Al₂O₃), aluminum nitride (AlN), siliconnitride (Si₃N₄) or the like. The insulating layer 3 made of theinsulating material has a thermal conductivity of 2 J/mKs or less, whichvaries depending upon film formation conditions or measurementconditions. In this case, the insulating layer 3 may be made of the samematerial as that of the top gap layer 5 or the bottom gap layer 2. Aportion of the insulating layer 3 in contact with at least an endsurface of the GMR film 20 on a side, the side being opposite to a sidefacing the magnetic recording medium 11 (that is, the ABS 19) preferablyhas a thickness A ranging from 2 nm to 30 nm inclusive in a directionperpendicular to the ABS 19. The reason will be described later.

[0073] As shown in Table 1, as the material of the heat dissipationlayer 4, a material with a higher thermal conductivity than the materialof the insulating layer 3 is used.

[0074] Next, effects of the embodiment will be described in contrast toa comparative example shown in FIG. 19. In the comparative example, aheat dissipation layer 104 is formed between a GMR film 120 and a bottomgap layer 102 so as to enhance heat dissipation. Even in the case of athin film magnetic head comprising a reproducing head portion 210A withsuch a structure, it can be expected that when a demand for a thinnerGMR device (a downsizing of a device including the GMR film 120 in athickness direction) grows in accordance with an even higher recordingdensity in future, it will be more difficult to secure sufficient heatdissipation. It is because as a result of not only a reduced area of alaminated surface but also a reduced thickness in an MR device, areduction in the thickness of the heat dissipation layer is required, sothe volume of the heat dissipation layer may not be able to besufficiently secured. Further, in the above reproducing head portion210A, heat dissipation in one of the layers constituting the GMR film120 disposed on a side far from the heat dissipation layer may not besufficiently carried out.

[0075] On the other hand, in the reproducing head portion 10A accordingto the embodiment shown in FIG. 6, the heat dissipation layer 4 with ahigher thermal conductivity than the insulating layer 3 is disposedadjacent to the GMR film 20 on a side opposite to the ABS 19 with thethin insulating layer 3 in between. In other words, the heat dissipationlayer 4 is disposed in a rear space (a side opposite to the ABS 19)corresponding to the thickness of the GMR film 20. Even if the heatdissipation layer 4 has as large a thickness as the whole thickness ofthe GMR film 20, the whole thickness of the MR device will neverincrease. Therefore, in spite of the GMR film 20 with a reduced size,the heat dissipation layer 4 can have a sufficient volume, so heat canbe sufficiently dissipated. Moreover, the heat dissipation layer 4 isdirectly in contact with all of the layers constituting the GMR film 20,so heat can be almost uniformly dissipated in a thickness direction (alaminated direction) of the GMR film 20. In other word, withoutincreasing the thickness of the reproducing head portion 10A, heat canbe uniformly and sufficiently dissipated.

[0076] Moreover, the material of the heat dissipation layer 4 has ahigher thermal conductivity than the material of the insulating layer 3,so compared to the case where the whole rear space corresponding to thethickness of the GMR film 20 is filled with the insulating layer 3, heatcan be efficiently dissipated.

[0077] Next, preferable ranges of the thickness A (of the insulatinglayer 3), the thickness C (of the heat dissipation layer 4) and thedistance B shown in FIG. 6 will be described below. The thicknesses Aand C are determined as follows in the viewpoint of securing heatdissipation and insulation.

[0078] The smaller (thinner) the thickness A of the insulating layer 3is, the more heat dissipation will be improved. In other word, thethinner the thickness A is, the more quickly heat generated in the GMRfilm 20 can be transferred to the heat dissipation layer 4. FIG. 7 showsa plot of a correlation between the thickness A and the MR height. Alateral axis of the plot indicates the thickness A, and a vertical axisof the plot indicates a ratio of the MR height required to keep thetemperature of the GMR film 20 constant on a basis that the ratio isequivalent to 100% in the case where the thickness A is 100 nm. Herein,the thickness C of the heat dissipation layer 4 is equivalent to 75% ofthe thickness of the GMR film 20. As shown in FIG. 7, the thinner thethickness A is, the more the MR height can be reduced. In other words,the thinner the thickness A is, the more heat dissipation will beimproved, and the more the size of the GMR film 20 can be reduced. Inthis case, it can be judged that when the thickness A is approximately30 nm or less, an effect of improving heat dissipation will be produced.However, the thickness A is required to be at least 2 nm in theviewpoint of securing insulation between the GMR film 20 and the heatdissipation layer 4.

[0079] The larger (thicker) the thickness C of the heat dissipationlayer 4 is, the more heat dissipation will be improved. In other words,the larger the thickness C is, the larger a portion corresponding to athickness direction of the GMR film 20 will be, so heat can beefficiently dissipated. FIG. 8 shows a plot of a correlation between thethickness C and the MR height. A lateral axis of the plot indicates aratio of the thickness C in the case where the thickness of the GMR film20 is equivalent to 100%, and a vertical axis of the plot indicates aratio of the MR height required to keep the temperature of the GMR film20 constant on a basis that the ratio of the MR height is equivalent to100% in the case where no heat dissipation layer 4 is disposed. As shownin FIG. 8, the thicker the thickness C is, the more heat dissipationwill be improved, and the more the size of the GMR film 20 can bereduced. In this case, it can be judged that when the thickness C has athickness equivalent to approximately 50% or over of the thickness ofthe GMR film 20, an effect of improving heat dissipation will beproduced. The upper limit of the thickness C is determined by thedistance B in viewpoint of securing insulation between the heatdissipation layer 4 and the bottom shield layer 1. The distance B ispreferably 2 nm or over.

[0080] Next, output characteristics of the thin film magnetic head 10according to the embodiment shown in FIG. 4 which is manufactured in theabove-described manner will be described in detail in contrast to aconventional example (refer to FIG. 18).

[0081]FIG. 9 shows a correlation between the MR height and a raisedtemperature during energization in the thin film magnetic head 10 shownin FIG. 4. A vertical axis of FIG. 9 indicates a raised temperature (°C.) of the GMR film 20 (120) during energization. A lateral axis of FIG.9 indicates a reciprocal of the MR height (“1/MR height”) on a basisthat the reciprocal is equivalent to 10 when the raised temperature is100° C. A magnitude Is of a sense current passing through the GMR film20 (120) is 4.0 mA. In FIG. 9, a curve 9A indicates a result of the thinfilm magnetic head 10, and a curve 9B indicates a result of theconventional example.

[0082] As indicated by the curve 9B, in the conventional example, inorder to limit the raised temperature to 50° C. or less, the “1/MRheight” is required to be approximately 6.8 or less, that is, the MRheight is required to have a length of {fraction (1/6.8)} or over. Onthe other hand, as indicated by the curve 9A, in the thin film magnetichead 10 according to the embodiment, when the “1/MR height” isapproximately 7.7 or less, that is, the MR height has a length of{fraction (1/7.7)} or over, the raised temperature can be limited to 50°C. or less. Therefore, the thin film magnetic head 10 according to theembodiment comprising the heat dissipation layer 4 has superior heatdissipation and an advantage in a downsizing of the MR device.

[0083]FIG. 10 shows a correlation between the MR height and an outputvoltage in the thin film magnetic head 10 shown in FIG. 4. A lateralaxis of FIG. 10 indicates the “1/MR height” corresponding to FIG. 9. Onthe other hand, a vertical axis of FIG. 10 indicates an output voltageon a basis that the output voltage is equivalent to 10 when the “1/MRheight” is 10.

[0084] As shown in FIG. 10, the smaller the MR height is, the more acurrent density is improved, so an improvement in the output voltage canbe expected. For example, in the conventional example, when the “1/MRheight” is 6.8 in which the raised temperature becomes 50° C., theoutput voltage is approximately 6.25. On the other hand, in the thinfilm magnetic head 10 according to the embodiment, when the “1/MRheight” is 7.7 in which the raised temperature becomes 50° C., theoutput voltage is approximately 7.25. In other words, when an acceptableraised temperature is 50° C., the minimum size of the MR height isreduced from {fraction (1/6.8)} to {fraction (1/7.7)}, thereby, theoutput voltage is improved from approximately 6.25 to approximately7.25, that is, an approximately 1.16 times improvement is achieved. Inother words, the thin film magnetic head 10 according to the embodimentcomprising the heat dissipation layer 4 can inhibit the temperature risein spite of a downsizing, so the output voltage can be further improved.

[0085] Next, a method of manufacturing the thin film magnetic head 10will be described below referring to drawings.

[0086] At first, referring to FIG. 11, a method of manufacturing amagnetic head apparatus will be described before describing a method ofmanufacturing the thin film magnetic head. FIG. 11 shows a flowchart ofa method of manufacturing the magnetic head apparatus 12 shown in FIG.1.

[0087] First of all, a substrate (not shown) made of AlTiC (a compositematerial of aluminum oxide and titanium carbide) or the like is prepared(step S101). The substrate will ultimately become the base substrate100, and has a region large enough to form a plurality of thin filmmagnetic heads 10 thereon. Next, on the substrate, the reproducing headportion 10A having a multilayer film 20A which will become the GMR film20 in a later step is formed (step S102), and on the reproducing headportion 10A, the recording head portion 10B is formed so as totentatively complete the thin film magnetic heads 10 (step S103). Then,the thin film magnetic heads 10 are cut into each line to form a bar ofthe thin film magnetic heads 10, and an end surface orthogonal to a filmforming surface of the bar of the thin film magnetic heads 10 ismechanically polished so as to form the ABS 19 (step S104). Then, afterthe bar is cut into individual thin film magnetic heads 10, each of theindividual thin magnetic heads 10 is processed into a predeterminedshape to form the slider 17 (step S105). Finally, the slider 17 ismounted on a slider supporting portion 12A to complete the magnetic headapparatus 12 (step S106). As described above, the magnetic headapparatus 12 shown in FIG. 1 is completed.

[0088] Next, referring to FIGS. 3 through 5 and FIGS. 12 through 16, amethod of manufacturing the thin film magnetic head 10 will be describedin detail below.

[0089] At first, mainly referring to FIGS. 12 through 16, a method ofmanufacturing the reproducing head portion 10A will be described below.FIGS. 12 through 16 are sectional views showing each step in a method ofmanufacturing a thin film magnetic head according to the embodiment.First of all, as shown in FIG. 12, after the bottom shield layer 1 madeof an electrically conductive magnetic material such as a NiFe alloy orthe like is formed on the substrate which will become the base substrate100 in a later step through sputtering or the like, the bottom gap layer2 made of aluminum oxide or the like is formed over the whole surface ofthe bottom shield layer 1. Next, the multilayer film 20A which willbecome the GMR film 20 with a spin-valve structure in a later step isformed over the whole surface of the bottom gap layer 2. Morespecifically, the base layer 21, the pinning layer 22, the pinned layer23, the non-magnetic layer 24, the magnetic sensing layer 25 and the caplayer 26 are laminated in order through sputtering or the like (refer toFIG. 5). Further, the photoresist layer 7 is selectively formed on themultilayer film 20A through photolithography. After that, as shown inFIG. 13, the multilayer film 20A and the bottom gap layer 2 areselectively etched through ion milling or the like by use of thephotoresist layer 7 as a mask. In an etching step, the multilayer film20A in a region which is not covered with the photoresist layer 7 isthoroughly removed in a thickness direction, and the bottom gap layer 2in a region which is not covered with the photoresist layer 7 is alsoremoved in a thickness direction in partway. Next, as shown in FIG. 14,the insulating layer 3 and the heat dissipation layer 4 are laminated inorder on an etched removed portion 8 through sputtering or the like. Bythe above step, the heat dissipation layer 4 is formed so as to bedisposed adjacent to the GMR film 20 on a side, the side being oppositeto a side facing the magnetic recording medium 11, and the insulatinglayer 3 sandwiched between the GMR film 20 and the heat dissipationlayer 4 is formed.

[0090] Next, as shown in FIG. 15, after the photoresist layer 7 islifted off, an unnecessary portion above an etching position 4A (in adirection away from the base substrate 100) is removed through reactiveion etching (RIE) or the like. Thus, as shown in FIG. 16, a top surfacecomposed of the multilayer film 20A, the insulating layer 3 and the heatdissipation layer 4 can be formed so as to be aligned flat. After that,a pair of the magnetic domain control layers 31, a pair of the firstlead layers 32 and a pair of the second lead layers (all not shown inFIG. 16) are laminated in a direction perpendicular to a paper surfaceof FIG. 16 so as to face each other with the multilayer film 20A inbetween. Then, the top gap layer 5 is formed through, for example,sputtering so that the whole surface is covered with the top gap layer5. Further, on the top gap layer 5, the top shield layer 6 made of anelectrically conductive magnetic material such as a NiFe alloy or thelike is selectively formed.

[0091] Thus, the formation of the reproducing head portion 10Acomprising the spin-valve type GMR film 20, the heat dissipation layer4, the insulating layer 3 and a path for flowing a current into the GMRfilm 20 in a direction perpendicular to a film forming surface (that is,the top shield layer 6, the top gap layer 5, the bottom gap layer 2 andthe bottom shield layer 1) is tentatively completed.

[0092] Next, referring to FIGS. 3 and 4, a method of manufacturing therecording head portion 10B formed on the reproducing head portion 10Awill be described below. Firstly, after the write gap layer 41 made ofan insulating material is selectively formed on the top shield layer 6through sputtering or the like, the write gap layer 41 is partiallyetched so as to form the opening 41A for forming a magnetic path.

[0093] Then, after the photoresist layer 42 is formed in a predeterminedpattern on the write gap layer 41, the coil 43 having a spiral shapearound the opening 41A as a center is formed. The photoresist layer 44which determines a throat height is formed in a predetermined pattern soas to coat the coil 43. The throat height is a distance from a front endof the photoresist layer 44 in which the coil 43 is embedded to the ABS19. Next, the coil 45 and the photoresist layer 46 are repeatedly formedon the photoresist layer 44 if necessary. In the embodiment, the coil islaminated in two layers, but the coil may be laminated in one layer orthree layers or more.

[0094] After the photoresist layer 46 is formed, the top pole 47 isselectively formed on the write gap layer 41, the opening 41A and thephotoresist layers 44 and 46. Next, the write gap layer 41 isselectively etched through ion milling or the like by use of the toppole 47 as a mask. Further, a resist layer (not shown) is formed, and byuse of the resist layer as a mask, a region of the top shield layer 6 inthe vicinity of a region where the ABS 19 is formed is selectivelyetched to a predetermined depth. Thereby, the formation of the recordinghead portion 10B is tentatively completed.

[0095] Finally, an overcoat layer (not shown) made of an insulatingmaterial such as aluminum oxide or the like is formed so that allcomponents including the top pole 47 are coated with the overcoat layer.Thus, the formation of the thin film magnetic head 10 comprising thereproducing head portion 10A and the recording head portion 10B iscompleted.

[0096] As described above, the thin film magnetic head 10 according tothe embodiment comprises the heat dissipation layer 4 which is formedadjacent to the GMR film 20 on a side opposite to the ABS 19, and has afunction of dissipating heat generated in the GMR film 20 to outside, soheat dissipation can be further improved. In other words, heat in theGMR film 20 is transferred to the heat dissipation layer 4 made of amaterial with a higher thermal conductivity through the thin insulatinglayer 3, thereby the heat can be efficiently dissipated. Accordingly, adownsizing of the MR device can be achieved without degradation in theoutput voltage due to increased electrical resistance or pronounceddegradation in reproducing characteristics due to internal diffusion inthe MR device.

[0097] More specifically, in the thin film magnetic head 10 according tothe embodiment, the heat dissipation layer 4 is disposed adjacent to theGMR film 20 in a direction orthogonal to the ABS 19, so the heatdissipation layer 4 with a sufficient volume can be provided without anyeffect due to a reduction in the MR height. Moreover, surroundings ofthe heat dissipation layer 4 are occupied by an insulating material, sovarious electrically conductive materials with a high thermalconductivity can be used as the heat dissipation layer 4 without concernfor constraints on electrical insulation.

[0098] [Second Embodiment]

[0099] Next, a second embodiment of the invention will be describedbelow. In the following description, like components are denoted by likenumerals as of the first embodiment and will not be further explained.

[0100] A thin film magnetic head according to the embodiment comprises amagnetic transducer film which is disposed so as to face a recordingmedium, a gap layer and a pair of shield layers, and a portion of thegap layer in contact with an end surface of the magnetic transducer filmon a side, the side being opposite to a side facing the recording mediumhas a thickness ranging from 2 nm to 30 nm inclusive. Herein, acharacteristic part different from the first embodiment, that is, onlythe structure of a reproducing head portion in the thin film magnetichead will be described below.

[0101] Referring to FIG. 17, the thin film magnetic head 10 according tothe second embodiment will be described in more detail. FIG. 17 shows asectional view of the structure of a reproducing head portion 10 aaccording to the embodiment. The reproducing head portion 10 a isdisposed so that one end surface thereof faces the magnetic recordingmedium 11, and comprises the GMR film 20 which detects a signal magneticfield from the magnetic recording medium 11, and a pair of shield layerswhich are disposed so as to surround the GMR film 20 except for one endsurface of the GMR film 20, and magnetically shields the GMR film 20,that is, the bottom shield layer 1 and the top shield layer 6. Gaplayers for electrically insulating between the GMR film 20 and thebottom and the top shield layer 1 and 6, that is, the bottom gap layer 2and the top gap layer 5 are formed therebetween, and a portion of thetop gap layer 5 in contact with an end surface 9 of the GMR film 20 on aside, the side being opposite to a side facing the magnetic recordingmedium 11 has a thickness ranging from 2 nm to 30 nm inclusive.

[0102] More specifically, as shown in FIG. 17, the reproducing headportion 10 a comprises, for example, a laminate including the bottomshield layer 1, the bottom gap layer 2, the GMR film 20, the top gaplayer 5 and the top shield layer 6 in order on the base substrate 100 ona side close to the ABS 19. In this case, the end surface 9 of the GMRfilm 20 on a side opposite to the ABS 19 is completely coated with thetop gap layer 5. The top gap layer 5 and the bottom gap layer 2 are incontact with each other on a side far from the end surface 9 when viewedfrom the ABS 19. A space behind a portion of the top gap layer 5 incontact with the end surface 9 (that is, a side opposite to the ABS 19)is completely filled with the top shield layer 6. A thickness a of theportion of the top gap layer 5 in contact with the end surface 9 is in arange from 2 nm to 30 nm inclusive. In this case, the top shield layer 6preferably occupies a space corresponding to at least half of thethickness of the GMR film 20. In other words, a thickness c in FIG. 17is preferably half or more of the thickness of the GMR film 20. Further,a distance b between the top shield layer 6 and the bottom shield layer1 is preferably 2 nm or over. Herein, the bottom gap layer 1 and the topgap layer 5 are made of, for example, aluminum oxide (Al₂O₃) with athermal conductivity of approximately 0.8 J/mKs. The bottom shield layer1 and the top shield layer 6 are made of a NiFe alloy with a higherthermal conductivity of approximately 22 J/mKs than those of the bottomgap layer 2 and the top gap layer 5, or the like.

[0103] In the reproducing head portion 10 a with such a structure,insulation between the GMR film 20 and the top and the bottom shieldlayers 6 and 1 can be secured, and heat can be efficiently transferredto the top shield layer 6 with a higher thermal conductivity than thetop gap layer 5, so a temperature rise of the GMR film 20 can beinhibited.

[0104] In the embodiment, output characteristics equivalent to thoseshown in FIGS. 9 and 10 in the first embodiment can be obtained.

[0105] As described above, the thin film magnetic head 10 according tothe embodiment comprises the GMR film 20 disposed so as to face themagnetic recording medium 11, the top and the bottom gap layers 5 and 2,and the top and the bottom shield layers 6 and 1, and a portion of thetop gap layer 5 in contact with the end surface 9 of the GMR film 20 ona side opposite to the ABS 19 has a thickness ranging from 2 nm to 30 nminclusive, so heat dissipation can be further improved. In other words,heat generated in the GMR film 20 is transferred to the top shield layer6 made of a material with a higher thermal conductivity through athinner portion of the top gap layer 5 so that the heat can beefficiently dissipated. Thereby, as in the case of the first embodiment,without degradation in output voltage due to increased electricalresistance or pronounced degradation in reproducing characteristics dueto internal diffusion in the MR device, a downsizing of the MR devicecan be achieved.

[0106] The invention is described with reference to some embodiments,but the invention is not limited to these embodiments, and can bevariously modified. For example, in the embodiments, the thin filmmagnetic head comprising the GMR film exposed to therecording-medium-facing surface (ABS) is described, but the invention isnot limited to this. The invention may be applicable to a thin filmmagnetic head having a structure in which the GMR film is comprised inthe interior thereof, and a magnetic path from the ABS to the GMR filmis formed with a flux guide or the like. Moreover, in the aboveembodiments, a CIP (current flow-in-the-plane of the layers) type thinfilm magnetic head is described, but the invention is not limited tothis, and is applicable to a CPP (current perpendicular-to-the-plane)type thin film magnetic head or a TMR (tunneling magnetoresistance)head.

[0107] As described above, in the thin film magnetic head, the method ofmanufacturing the thin film magnetic head or the magnetic disk driveaccording to an aspect of the invention, the heat dissipation layerbeing disposed adjacent to the magnetic transducer film on a side, theside being opposite to a side facing the recording medium, andtransferring heat generated in the magnetic transducer film to outsideis comprised, so the heat generated in the magnetic transducer film canbe more effectively dissipated than previously possible, thereby atemperature rise can be inhibited. Therefore, even if the size of themagnetic transducer film is reduced, an increase in electricalresistance can be inhibited, and a higher read output can be obtained.

[0108] More specifically, in the thin film magnetic head or the methodof manufacturing the thin film magnetic head according to the aspect ofthe invention, the insulating layer is disposed between the magnetictransducer film and the heat dissipation layer, so even if the heatdissipation layer is made of an electrically conductive material, asense current can be prevented from being diverted to the heatdissipation layer.

[0109] Moreover, in the thin film magnetic head or the method ofmanufacturing the thin film magnetic head according to the aspect of theinvention, the thickness of the heat dissipation layer corresponds to atleast half of the thickness of the magnetic transducer film, so heatdissipation can be more effectively obtained.

[0110] Further, in the thin film magnetic head or the method ofmanufacturing the thin film magnetic head according to another aspect ofthe invention, the magnetic transducer film disposed so as to face therecording medium, a pair of shield layers and the gap layer forinsulating between the magnetic transducer film and the pair of shieldlayers are comprised, a portion of the gap layer in contact with an endsurface of the magnetic transducer film on a side opposite a side facingthe recording medium is formed with a thin thickness ranging from 2 nmto 30 nm inclusive, so heat dissipation can be improved more thanpreviously possible. In other words, the heat generated in the magnetictransducer film is transferred to either of the pair of shield layerswith a higher thermal conductivity through the thinner portion of thegap layer, thereby the heat can be efficiently dissipated, and atemperature rise can be inhibited. Therefore, even if the size of themagnetic transducer film is reduced, an increase in electricalresistance can be inhibited, and a higher read output can be obtained.

[0111] Obviously many modifications and variations of the presentinvention are possible in the light of the above teachings. It istherefore to be understood that within the scope of the appended claimsthe invention may be practiced otherwise than as specifically described.

What is claimed is:
 1. A thin film magnetic head, comprising: a magnetictransducer film being disposed so that an end surface thereof faces arecording medium, and detecting a signal magnetic field from therecording medium; and a heat dissipation layer being disposed adjacentto the magnetic transducer film on a side, the side being opposite to aside facing the recording medium, and transferring heat generated in themagnetic transducer film to outside.
 2. A thin film magnetic headaccording to claim 1, further comprising: an insulating layer betweenthe magnetic transducer film and the heat dissipation layer.
 3. A thinfilm magnetic head according to claim 2, wherein the heat dissipationlayer is made of a material with a higher thermal conductivity than thatof the insulating layer.
 4. A thin film magnetic head according to claim1, wherein the heat dissipation layer is made of a non-magnetic metallicmaterial.
 5. A thin film magnetic head according to claim 1, wherein theheat dissipation layer includes at least one selected from the groupconsisting of silver (Ag), aluminum (Al), gold (Au), beryllium (Be),bismuth (Bi), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), indium(In), iridium (Ir), magnesium (Mg), manganese (Mn), molybdenum (Mo),niobium (Nb), nickel (Ni), palladium (Pd), platinum (Pt), rhenium (Re),antimony (Sb), selenium (Se), tantalum (Ta), tellurium (Te), thorium(Th), titanium (Ti), thallium (Tl), vanadium (V), tungsten (W), yttrium(Y) and zirconium (Zr).
 6. A thin film magnetic head according to claim1, wherein the heat dissipation layer is disposed adjacent to themagnetic transducer film so as to have a thickness corresponding to atleast half of the thickness of the magnetic transducer film.
 7. A thinfilm magnetic head according to claim 1, further comprising: a pair ofshield layers being disposed so as to face each other with the magnetictransducer film in between in a laminated direction, and magneticallyshielding the magnetic transducer film; and a pair of gap layers beingdisposed between the magnetic transducer film and the pair of shieldlayers, and electrically insulating between the magnetic transducer filmand the pair of shield layers.
 8. A thin film magnetic head according toclaim 7, wherein a distance between the heat dissipation layer and eachof the pair of shield layers is 2 nm or over.
 9. A thin film magnetichead according to claim 7, wherein the insulating layer is made of thesame material as that of the pair of gap layers.
 10. A thin filmmagnetic head according to claim 2, wherein a portion of the insulatinglayer in contact with an end surface of the magnetic transducer film ona side, the side being opposite to a side facing the recording mediumhas a thickness ranging from 2 nm to 30 nm inclusive.
 11. A thin filmmagnetic head, comprising: a magnetic transducer film being disposed sothat an end surface thereof faces a recording medium, and detecting asignal magnetic field from the recording medium; a pair of shield layersbeing disposed so as to surround an end surface of the magnetictransducer film on a side opposite to the end surface thereof, and filmsurfaces of the magnetic transducer film facing each other, andmagnetically shielding the magnetic transducer film; and a gap layerbeing disposed between the magnetic transducer film and the pair ofshield layers, and electrically insulating therebetween, wherein aportion of the gap layer in contact with the end surface of the magnetictransducer film on a side, the side being opposite to a side facing therecording medium has a thickness ranging from 2 nm to 30 nm inclusive.12. A thin film magnetic head according to claim 11, wherein the pair ofshield layers occupy a space corresponding to at least half of thethickness of the magnetic transducer film, and have a distance of atleast 2 nm therebetween.
 13. A method of manufacturing a thin filmmagnetic head, the thin film magnetic head comprising a magnetictransducer film being disposed so that an end surface thereof faces arecording medium, and detecting a signal magnetic field from therecording medium, the method comprising the steps of: forming themagnetic transducer film; and forming a heat dissipation layer fortransferring heat generated in the magnetic transducer film to outsideso as to be disposed adjacent to the magnetic transducer film on a side,the side being opposite to a side facing the recording medium.
 14. Amethod of manufacturing a thin film magnetic head according to claim 13,further comprising the step of: forming an insulating layer between themagnetic transducer film and the heat dissipation layer.
 15. A method ofmanufacturing a thin film magnetic head according to claim 14, whereinin the step of forming the heat dissipation layer, the heat dissipationlayer is made of a material with a higher thermal conductivity than thatof the insulating layer.
 16. A method of manufacturing a thin filmmagnetic head according to claim 13, wherein in the step of forming theheat dissipation layer, the heat dissipation layer is made of anon-magnetic metallic material.
 17. A method of manufacturing a thinfilm magnetic head according to claim 13, wherein in the step of formingthe heat dissipation layer, the heat dissipation layer is formed so asto include at least one selected from the group consisting of silver(Ag), aluminum (Al), gold (Au), beryllium (Be), bismuth (Bi), cobalt(Co), chromium (Cr), copper (Cu), iron (Fe), indium (In), iridium (Ir),magnesium (Mg), manganese (Mn), molybdenum (Mo), niobium (Nb), nickel(Ni), palladium (Pd), platinum (Pt), rhenium (Re), antimony (Sb),selenium (Se), tantalum (Ta), tellurium (Te), thorium (Th), titanium(Ti), thallium (Ti), vanadium (V), tungsten (W), yttrium (Y) andzirconium (Zr).
 18. A method of manufacturing a thin film magnetic headaccording to claim 13, wherein in the step of forming the heatdissipation layer, the thickness of the heat dissipation layer is halfor more of the thickness of the magnetic transducer film.
 19. A methodof manufacturing a thin film magnetic head according to claim 13,further comprising the steps of: forming a pair of shield layers formagnetically shielding the magnetic transducer film so as to face eachother with the magnetic transducer film in between; and forming a pairof gap layers for electrically insulating between the magnetictransducer film and the pair of shield layers so as to be disposedbetween the magnetic transducer film and the pair of shield layers. 20.A method of manufacturing a thin film magnetic head according to claim19, wherein in the step of forming the pair of shield layers, a distancebetween the heat dissipation layer and each of the pair of shield layersis 2 nm or over.
 21. A method of manufacturing a thin film magnetic headaccording to claim 19, wherein in the step of forming the insulatinglayer, the insulating layer is made of the same material as that of thepair of gap layers.
 22. A method of manufacturing a thin film magnetichead according to claim 14, wherein in the step of forming theinsulating layer, the insulating layer is formed so that a portion ofthe insulating layer in contact with at least an end surface of themagnetic transducer film on a side, the side being opposite to a sidefacing the recording medium has a thickness ranging from 2 nm to 30 nminclusive.
 23. A method of manufacturing a thin film magnetic head, thethin film magnetic head comprising a magnetic transducer film beingdisposed so that an end surface thereof faces a recording medium, anddetecting a signal magnetic field from the recording medium, a pair ofshield layers magnetically shielding the magnetic transducer film, and agap layer electrically insulating between the magnetic transducer filmand the pair of shield layers, the method comprising the steps of:forming the magnetic transducer film; forming the pair of shield layersso as to surround an end surface of the magnetic transducer film on aside opposite to the end surface thereof, and film surfaces of themagnetic transducer film facing each other; and forming the gap layerbetween the magnetic transducer film and the pair of shield layers sothat a portion of the gap layer in contact with the end surface of themagnetic transducer film on a side, the side being opposite to a sidefacing the recording medium has a thickness ranging from 2 nm to 30 nminclusive.
 24. A method of manufacturing a thin film magnetic headaccording to claim 23, wherein in the step of forming the pair of shieldlayers, the pair of shield layers occupy a space corresponding to atleast half of the thickness of the magnetic transducer film, and has adistance of at least 2 nm therebetween.
 25. A magnetic disk drive,comprising: a recording medium; and a thin film magnetic head, whereinthe thin film magnetic head comprises: a magnetic transducer film beingdisposed so that an end surface thereof faces the recording medium, anddetecting a signal magnetic field from the recording medium, and a heatdissipation layer being disposed adjacent to the magnetic transducerfilm on a side, the side being opposite to a side facing the recordingmedium, and transferring heat generated in the magnetic transducer filmto outside.
 26. A magnetic disk drive, comprising: a recording medium;and a thin film magnetic head, wherein the thin film magnetic headcomprises: a magnetic transducer film being disposed so that an endsurface thereof faces the recording medium, and detecting a signalmagnetic field from the recording medium, a pair of shield layers beingdisposed so as to surround an end surface of the magnetic transducerfilm on a side opposite to the end surface thereof, and film surfaces ofthe magnetic transducer film facing each other, and magneticallyshielding the magnetic transducer film, and a gap layer being disposedbetween the magnetic transducer film and the pair of shield layers, andelectrically insulating therebetween, wherein a portion of the gap layerin contact with the end surface of the magnetic transducer film on aside, the side being opposite to a side facing the recording medium hasa thickness ranging from 2 nm to 30 nm inclusive.